Method and apparatus for indicating semi-persistent sounding reference signal as reference signal of neighboring cell in next-generation mobile communication system

ABSTRACT

A communication method and a system for converging a 5th generation (5G) communication system for supporting higher data rates beyond a 4th generation (4G) system with a technology for internet of things (IoT) are provided. The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. Disclosed is a method of performing activation and deactivation of a semi-persistent sounding reference signal (SP SRS) through a medium access control element (MAC CE) when activation/deactivation of the SP SRS is indicated in a next-generation mobile communication system.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. §119(a) of a Korean patent application number 10-2018-0053464, filed onMay 10, 2018, in the Korean Intellectual Property Office, the disclosureof which is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The disclosure relates to an operation of a user equipment (UE) and anevolved node B (eNB) in a mobile communication system. Moreparticularly, the present disclosure relates to a method ofactivating/deactivating a semi-persistent sounding reference signal in anext-generation mobile communication system.

2. Description of Related Art

To meet the demand for wireless data traffic having increased sincedeployment of 4^(th) generation (4G) communication systems, efforts havebeen made to develop an improved 5^(th) generation (5G) or pre-5Gcommunication system. Therefore, the 5G or pre-5G communication systemis also called a ‘Beyond 4G Network’ or a ‘Post LTE System’. The 5Gcommunication system is considered to be implemented in higher frequency(mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher datarates. To decrease propagation loss of the radio waves and increase thetransmission distance, the beamforming, massive multiple-inputmultiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques are discussed in5G communication systems. In addition, in 5G communication systems,development for system network improvement is under way based onadvanced small cells, cloud radio access networks (RANs), ultra-densenetworks, device-to-device (D2D) communication, wireless backhaul,moving network, cooperative communication, coordinated multi-points(CoMP), reception-end interference cancellation and the like. In the 5Gsystem, Hybrid FSK and QAM modulation (FQAM) and sliding windowsuperposition coding (SWSC) as an advanced coding modulation (ACM), andfilter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA),and sparse code multiple access (SCMA) as an advanced access technologyhave been developed.

The Internet, which is a human centered connectivity network wherehumans generate and consume information, is now evolving to the internetof things (IoT) where distributed entities, such as things, exchange andprocess information without human intervention. The internet ofeverything (IoE), which is a combination of the IoT technology and theBig Data processing technology through connection with a cloud server,has emerged. As technology elements, such as “sensing technology”,“wired/wireless communication and network infrastructure”, “serviceinterface technology”, and “Security technology” have been demanded forIoT implementation, a sensor network, a machine-to-machine (M2M)communication, machine type communication (MTC), and so forth have beenrecently researched. Such an IoT environment may provide intelligentInternet technology services that create a new value to human life bycollecting and analyzing data generated among connected things. IoT maybe applied to a variety of fields including smart home, smart building,smart city, smart car or connected cars, smart grid, health care, smartappliances and advanced medical services through convergence andcombination between existing information technology (IT) and variousindustrial applications.

In line with this, various attempts have been made to apply 5Gcommunication systems to IoT networks. For example, technologies, suchas a sensor network, MTC, and M2M communication may be implemented bybeamforming, MIMO, and array antennas. Application of a cloud radioaccess network (RAN) as the above-described Big Data processingtechnology may also be considered to be as an example of convergencebetween the 5G technology and the IoT technology.

When activation/deactivation of a semi-persistent sounding referencesignal (SP SRS) in a next-generation mobile communication system isindicated, a beam through which the corresponding SP SRS is transmitted,that is, a quasi-co-located (QCLed) beam, may be indicated. A method bywhich a user equipment (UE) and an evolved node B (eNB) transmit andreceive SP SRS signals through appropriate directional beams is needed.

The above information is presented as background information only toassist with an understanding of the disclosure. No determination hasbeen made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the disclosure.

SUMMARY

Aspects of the disclosure are to address at least the above-mentionedproblems and/or disadvantages and to provide at least the advantagesdescribed below. Accordingly, an aspect of the disclosure is to providea method of activating/deactivating a semi-persistent sounding referencesignal in a next-generation mobile communication system.

Another aspect of the disclosure is to provide a method of generating amedium access control (MAC) control element (CE) for, when a beamthrough which the corresponding sounding reference signal to betransmitted is indicated, indicating not only the current serving celland a bandwidth part (BWP) but also a neighboring serving cell and aBWP.

Another aspect of the disclosure is to provide a procedure and a methodfor providing a flow-based quality of service (QoS) introduced in anext-generation mobile communication system and extending a QoS flowidentification (ID) since a 6-bit QoS flow ID within a current 1-byteservice data access protocol (SDAP) header is insufficient to expressall services for a new QoS layer (SDAP) indicating a change in aflow-mapping rule of an access stratum (AS) and a non-access stratum(NAS) to wireless protocols of a user equipment (UE) and an evolved NodeB (eNB) through a user data packet.

An embodiment of the disclosure is to provide an efficient communicationmethod.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to an embodiment of the disclosure, it is possible to indicatenot only a current serving cell and a BWP but also a neighboring servingcell and a BWP when a semi-persistent sounding reference signal isactivated/deactivated through a MAC CE in a next-generation mobilecommunication system.

According to another embodiment of the disclosure, it is possible todistinguish and support various services by supporting flow-based QoSthrough a wireless interface and then supporting extension of the QoSflow in a next-generation mobile communication system.

In accordance with an aspect of the disclosure, a method of indicating asemi-persistent (SP) sounding reference signal (SRS) as a referencesignal by a terminal is provided. The method includes receiving, from abase station, information for an SRS configuration, receiving, from thebase station, a MAC CE for activating the SP SRS, and transmitting, tothe base station, an SRS on a first cell based on the information forthe SRS configuration and the MAC CE for activating the SP SRS, whereinthe MAC CE for activating the semi-persistent SP SRS includes anindicator for indicating whether serving cell information and BWPinformation for a reference signal associated with spatial relationshipare present.

In accordance with another aspect of the disclosure, a terminal isprovided. The terminal includes a transceiver, and at least oneprocessor coupled with the transceiver and configured to receiveinformation for a SRS configuration, to receive a MAC CE for activatinga SP SRS, and to transmit an SRS on a first cell based on theinformation for the SRS configuration and the MAC CE for activating theSP SRS, wherein the MAC CE for activating the SP SRS includes anindicator for indicating whether serving cell information and BWPinformation for a reference signal associated with spatial relationshipare present.

In accordance with another aspect of the disclosure, a method ofindicating an SP SRS as a reference signal by a terminal is provided.The method includes transmitting, to a terminal, information for a SRSconfiguration, transmitting, to the terminal, a MAC CE for activating aSP SRS, and receiving, from the terminal, an SRS on a first cell basedon the information for the SRS configuration and the MAC CE foractivating the SP SRS, wherein the MAC CE for activating the SP SRSincludes an indicator for indicating whether serving cell informationand BWP information for a reference signal associated with spatialrelationship are present.

In accordance with another aspect of the disclosure, a base station isprovided. The base station includes a transceiver, and at least oneprocessor coupled with the transceiver and configured to transmit, to aterminal, information for a SRS configuration, to transmit, to theterminal, a MAC CE for activating a SP SRS, and to receive, from theterminal, an SRS on a first cell based on the information for the SRSconfiguration and the MAC CE for activating the SP SRS, wherein the MACCE for activating the SP SRS includes an indicator for indicatingwhether serving cell information and BWP information for a referencesignal associated with spatial relationship are present.

Other aspects, advantages, and salient features of the disclosure willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses various embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1A illustrates a structure of a next-generation mobilecommunication system according to an embodiment of the disclosure;

FIG. 1B illustrates a structure of a next-generation mobilecommunication system according to an embodiment of the disclosure;

FIG. 1C illustrates a frame structure used by a new radio (NR) systemaccording to an embodiment of the disclosure;

FIG. 1D illustrates a wireless protocol structure of a next-generationmobile communication system according to an embodiment of thedisclosure;

FIG. 1E illustrates a case in which network triggering beam switchingthrough a medium access control (MAC) control element (CE) issuccessfully performed according to an embodiment of the disclosure;

FIG. 1F illustrates MAC CE format method 1 of configuring a referencesignal of a neighboring cell as a beam of a semi-persistent soundingreference signal according to an embodiment of the disclosure;

FIG. 1G illustrates MAC CE format method 2 of configuring a referencesignal of a neighboring cell as a beam of a semi-persistent soundingreference signal according to an embodiment of the disclosure;

FIG. 1H illustrates MAC CE format method 3 of configuring a referencesignal of a neighboring cell as a beam of a semi-persistent soundingreference signal according to an embodiment of the disclosure;

FIG. 1I is a block diagram illustrating an internal structure of a UEaccording to an embodiment of the disclosure;

FIG. 1J is a block diagram illustrating a configuration of an NR NBaccording to an embodiment of the disclosure;

FIG. 2A illustrates a structure of a next-generation mobilecommunication system according to an embodiment of the disclosure;

FIG. 2B illustrates a wireless protocol structure of a next-generationmobile communication system according to an embodiment of thedisclosure;

FIG. 2C schematically illustrates an operation from a core network (CN)to a UE for processing a quality of service (QoS) in an NR systemaccording to an embodiment of the disclosure;

FIGS. 2DA and 2DB illustrate new functions for handling a QoS in an NRsystem according to an embodiment of the disclosure;

FIGS. 2EA and 2EB illustrate a protocol stack including a service dataaccess protocol (SDAP) in NR according to an embodiment of thedisclosure;

FIG. 2F illustrates a method of fixedly configuring a QoS flowidentification (ID) having an extended length according to an embodimentof the disclosure;

FIG. 2G illustrates method 1 of dynamically configuring a QoS flow IDhaving an extended length according to an embodiment of the disclosure;

FIG. 2H illustrates method 2 of dynamically configuring a QoS flow IDhaving an extended length according to an embodiment of the disclosure;

FIG. 2I illustrates an overall QoS processing operation to which a QoSmapping rule between a CN and a UE is applied according to an embodimentof the disclosure;

FIG. 2JA illustrates a QoS-related operation, particularly, a method ofconfiguring and using a QFI of an SDAP header by a UE in anext-generation mobile communication system according to an embodimentof the disclosure,

FIG. 2JB illustrates a QoS-related operation, particularly, a method ofconfiguring and using a QFI of an SDAP header by a UE in anext-generation mobile communication system according to an embodimentof the disclosure;

FIG. 2K is a block diagram illustrating an internal structure of a UE toaccording to an embodiment of the disclosure; and

FIG. 2L is a block diagram illustrating a configuration of an NR NBaccording to an embodiment of the disclosure.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thedisclosure. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of thedisclosure. Accordingly, it should be apparent to those skilled in theart that the following description of various embodiments of thedisclosure is provided for illustration purpose only and not for thepurpose of limiting the disclosure as defined by the appended claims andtheir equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

In describing the various embodiments of the disclosure, descriptionsrelated to technical contents which are well-known in the art to whichthe disclosure pertains, and are not directly associated with thedisclosure, will be omitted. Such an omission of unnecessarydescriptions is intended to prevent obscuring of the main idea of thedisclosure and more clearly transfer the main idea.

For the same reason, in the accompanying drawings, some elements may beexaggerated, omitted, or schematically illustrated. Further, the size ofeach element does not entirely reflect the actual size. In the drawings,identical or corresponding elements are provided with identicalreference numerals.

In accordance with an aspect of the disclosure, a method of indicatingan SP SRS as a reference signal by a terminal is provided. The methodincludes receiving, from a base station, information for a soundingreference signal (SRS) configuration, receiving, from the base station,a medium access control (MAC) control element (CE) for activating asemi-persistent (SP) SRS, and transmitting, to the base station, an SRSon a first cell based on the information for the SRS configuration andthe MAC CE for activating the SP SRS, wherein the MAC CE for activatingthe SP SRS includes an indicator for indicating whether serving cellinformation and bandwidth part (BWP) information for a reference signalassociated with spatial relationship are present.

The advantages and features of the disclosure and ways to achieve themwill be apparent by making reference to embodiments as described belowin conjunction with the accompanying drawings. However, the disclosureis not limited to the embodiments set forth below, but may beimplemented in various different forms. The following embodiments areprovided only to completely disclose the disclosure and inform thoseskilled in the art of the scope of the disclosure, and the disclosure isdefined only by the scope of the appended claims. Throughout thespecification, the same or like reference numerals designate the same orlike elements.

Here, it will be understood that each block of the flowchartillustrations, and combinations of blocks in the flowchartillustrations, can be implemented by computer program instructions.These computer program instructions can be provided to a processor of ageneral purpose computer, special purpose computer, or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, create means forimplementing the functions specified in the flowchart block or blocks.These computer program instructions may also be stored in a computerusable or computer-readable memory that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer usable orcomputer-readable memory produce an article of manufacture includinginstruction means that implement the function specified in the flowchartblock or blocks. The computer program instructions may also be loadedonto a computer or other programmable data processing apparatus to causea series of operations to be performed on the computer or otherprogrammable apparatus to produce a computer implemented process suchthat the instructions that execute on the computer or other programmableapparatus provide operations for implementing the functions specified inthe flowchart block or blocks.

And each block of the flowchart illustrations may represent a module,segment, or portion of code, which includes one or more executableinstructions for implementing the specified logical function(s). Itshould also be noted that in some alternative implementations, thefunctions noted in the blocks may occur out of the order. For example,two blocks shown in succession may in fact be executed substantiallyconcurrently or the blocks may sometimes be executed in the reverseorder, depending upon the functionality involved.

As used herein, the “unit” refers to a software element or a hardwareelement, such as a field programmable gate array (FPGA) or anapplication specific integrated circuit (ASIC), which performs apredetermined function. However, the “unit does not always have ameaning limited to software or hardware. The “unit” may be constructedeither to be stored in an addressable storage medium or to execute oneor more processors. Therefore, the “unit” includes, for example,software elements, object-oriented software elements, class elements ortask elements, processes, functions, properties, procedures,sub-routines, segments of a program code, drivers, firmware,micro-codes, circuits, data, database, data structures, tables, arrays,and parameters. The elements and functions provided by the “unit” may beeither combined into a smaller number of elements, “unit” or dividedinto a larger number of elements, “unit”. Moreover, the elements and“units” may be implemented to reproduce one or more central processingunits (CPUs) within a device or a security multimedia card.

First Embodiment

Hereinafter, an operating principle of the disclosure will be describedwith reference to the accompanying drawings. In describing thedisclosure below, a detailed description of related known configurationsor functions incorporated herein will be omitted when it is determinedthat the detailed description thereof may unnecessarily obscure thesubject matter of the disclosure. The terms which will be describedbelow are terms defined in consideration of the functions in thedisclosure, and may be different according to users, intentions of theusers, or customs. Therefore, the definitions of the terms should bemade based on the contents throughout the specification. In thefollowing description, terms for identifying an access node, termsreferring to network entities, terms referring to messages, termsreferring to interfaces between network entities, and terms referring tovarious pieces of identification information are used for convenience ofdescription. Therefore, the disclosure is not limited by theterminologies provided below, and other terms that indicate subjectshaving equivalent technical meanings may be used.

For convenience of description, the disclosure uses terms and namesdefined in a 3rd-generation partnership project, long-term evolution(3GPP LTE) standard or terms and names changed on the basis thereof.However, the disclosure is not limited to the terms and names and may beequally applied to a system according to another standard.

FIG. 1A illustrates a structure of a next-generation mobilecommunication system according to an embodiment of the disclosure.

Referring to FIG. 1A, a radio access network (RAN) of thenext-generation mobile communication system may include anext-generation evolved Node B (eNB) (NR gNB) or new radio node B (NRNB) 1 a-10 and an NR core network (NR CN) node 1 a-05. A terminal or anew radio user equipment (hereinafter referred to as a NR UE, a UE, or aterminal) 1 a-15 may access an external network 1 a-35 via the NR NB 1a-10 and the NR CN node 1 a-05.

In FIG. 1A, the NR gNB 1 a-10 corresponds to an evolved Node B (eNB) ofa conventional LTE system. The NR gNB 1 a-10 may be connected to the NRUE 1 a-15 through a radio channel and may provide better service than aconventional node B. Since all user traffic is served through a sharedchannel in the next-generation mobile communication system, a device forcollecting and scheduling status information of buffer statuses,available transmission power statuses, and channel statuses of UEs isrequired, and corresponds to the NR gNB 1 a-10. One NR gNB 1 a-10generally controls a plurality of cells. The NR NB may have a bandwidthwider than the conventional maximum bandwidth in order to implementsuper-high-speed data transmission compared to conventional LTE, and mayapply orthogonal frequency-division multiplexing (OFDM) through radioaccess technology, and may further apply beamforming technology.Further, an AMC (Adaptive Modulation and Coding) scheme of determining amodulation scheme and a channel coding rate is applied depending on thechannel status of the UE. The NR CN 1 a-05 performs a function ofsupporting mobility, establishing a bearer, and configuring QoS. The NRCN 1 a-05 serves to perform a function of managing the mobility of theUE and perform various control functions, and is connected to aplurality of eNBs. Further, the next-generation mobile communicationsystem may be linked to the conventional LTE system, and the NR CN 1a-05 is connected to an MME 1 a-25 through a network interface. The MME1 a-25 is connected to an eNB 1 a-30, which is the conventional eNB.

FIG. 1B illustrates a structure of a next-generation mobilecommunication system according to an embodiment of the disclosure.

Referring to FIG. 1B, a cell served by the NR gNB 1 b-05 operating basedon the beam may include a plurality of transmission reception points(TRPs) 1 b-10, 1 b-15, 1 b-20, 1 b-25, 1 b-30, 1 b-35, and 1 b-40. TheTRPs 1 b-10 to 1 b-40 indicate blocks separating some functions oftransmitting and receiving physical signals by the LTE eNB of therelated art and include a plurality of antennas. The NR gNB 1 b-05 maybe expressed as a central unit (CU) and the TRP may be expressed as adistributed unit (DU). Functions of the NR gNB 1 b-05 and the TRP may beconfigured by separated layers, such as packet data convergence protocol(PDCP)/radio link control (RLC)/MAC/PHY layers 1 b-45. For example, TRPs1 b-015 and 1 b-25 may have only the PHY layer and perform a function ofthe corresponding layer, TRPs 1 b-10, 1 b-35, and 1 b-40 may have onlythe PHY layer and the MAC layer and perform a function of thecorresponding layers, and TRPs 1 b-20 and 1 b-30 may have only the PHYlayer, the MAC layer, and the RLC layer and perform a function of thecorresponding layers. Particularly, the TRPs 1 b-10 to 1-40 may use abeamforming technology in which data is transmitted and received bygenerating narrow beams in various directions through a plurality oftransmission/reception antennas. A UE 1 b-50 accesses the NR gNB 1 b-05and the external network through the TRPs 1 b-10 to 1 b-40. In order toprovide a service to users, the NR gNB 1 b-05 collects and schedulesstatus information, such as buffer statuses, available transmissionpower statuses, and channel statuses of UEs and supports connectionbetween the UEs and a core network (CN).

FIG. 1C illustrates a frame structure used by an NR system according toan embodiment of the disclosure.

Referring to FIG. 1C, the NR system aims to realize a highertransmission rate than LTE and considers a scenario of operation in ahigh frequency in order to secure a wide frequency bandwidth.Particularly, in the high frequency, a scenario of generating adirectional beam and transmitting data to the UE at a high datatransmission rate may be considered.

Accordingly, during communication with UEs 1 c-71, 1 c-73, 1 c-75, 1c-77, and 1 c-79 within a cell, the NR NB or the transmission receptionpoint (TRP) 1 c-01 may communicate using different beams. For example,the scenario is assumed in which UE #1 1 c-71 communicates through beam#1 1 c-51, UE #2 1 c-73 communicates through beam #5 1 c-55, and UEs #3,#4, and #5 1 c-75, 1 c-77, and 1 c-79 communicate through beam #7 1c-57.

In order to identify the beam through which the UE communicates with theTRP, an overhead subframe (OSF) 1 c-03 for transmitting a commonoverhead signal exists on the time domain. The OSF includes a primarysynchronization signal (PSS) for acquiring timing of an OFDM symbol, asecondary synchronization signal (SSS) for detecting a cellidentification (ID), an extended synchronization signal (ESS) foracquiring timing of a subframe, and a beam reference signal (BRS) foridentifying a beam. Further, system information, a master informationblock (MIB), or a physical broadcast channel (PBCH) includinginformation required for access of the UE to the system (for example,including a bandwidth of the downlink beam and a system frame number)may be transmitted. Further, the NR NB transmits a reference signalusing a different beam for each symbol (or for several symbols) in theOSF. A beam index for identifying each beam may be derived from thereference signal. It is assumed that there are 12 beams from beam #1 1c-51 to beam #12 1 c-62 transmitted by the NR NB and that a differentbeam is swept for every symbol in the OSF in the example figure. Forexample, each beam may be transmitted for a corresponding symbol in theOSF (for example, beam #1 1 c-51-#12 1 c-42 are transmitted in symbol 1c-31-1 c-42), respectively, and the terminal may identify which signalis strongest and which beam the signal comes from by measuring the OSF.

The example figure assumes a scenario in which the corresponding OSFrepeats every 25 subframes and the remaining 24 subframes are datasubframes (hereinafter, referred to as DSF 1 c-05) in which general datais transmitted and received. Accordingly, a scenario is assumed in whichUEs 3, 4, and 5 1 c-75, 1 c-77, and 1 c-79 communicate in common usingbeam #7 according to scheduling of the NR gNB as indicated by referencenumeral 1 c-11, UE 1 1 c-71 communicates using beam #1 as indicated byreference numeral 1 c-13, and UE 2 1 c-73 communicates using beam #5 asindicated by reference numeral 1 c-15. The example figure mainlyillustrates transmission beams #1 1 c-51 to beam #12 1 c-62 of the NRgNB, but reception beams of the UE (for example, beams 1 c-81, 1 c-83, 1c-85, and 1 c-87 of UE 1) for receiving the transmission beams of the NRgNB may be additionally considered. In the example figure, UE 1 has fourbeams 1 c-81, 1 c-83, 1 c-85, and 1 c-87 and performs beam sweeping inorder to determine which beam has the best reception performance. Atthis time, when a plurality of beams cannot be simultaneously used, itis possible to find the optimal transmission beam of the NR gNB and theoptimal reception beam of the UE by using one reception beam for eachOSF and receiving a plurality of OSFS corresponding to the number ofreception beams.

FIG. 1D illustrates a wireless protocol structure of a next-generationmobile communication system according to an embodiment of thedisclosure.

Referring to FIG. 1D, the wireless protocol of the next-generationmobile communication system includes NR PDCPs 1 d-05 and 1 d-40, NRRLCs-10 and 1 d-35, and NR MACs 1 d-15 and 1 d-30 in the UE and the NRNB. The main functions of the NR PDCP 1 d-05 or 1 d-40 may include someof the following functions.

Header compression and decompression function (Header compression anddecompression: robust header compression (ROHC) only)

User data transmission function

Sequential delivery function (In-sequence delivery of upper layer PDUs)

Reordering function (PDCP PDU reordering for reception)

Duplicate detection function (Duplicate detection of lower layer SDUs)

Retransmission function (Retransmission of PDCP SDUs)

Ciphering and deciphering function (Ciphering and deciphering)

Timer-based SDU removal function (Timer-based SDU discard in uplink)

The reordering function of the NR PDCP device is a function ofsequentially reordering PDCP PDUs received from a lower layer based on aPDCP sequence number (SN), and may include a function of sequentiallytransferring the reordered data to a higher layer, a function ofrecording PDCP PDUs lost due to the reordering, a function of reportingstatuses of the lost PDCP PDUs to a transmitting side, and a function ofmaking a request for retransmitting the lost PDCP PDUs.

The main functions of the NR RLC 1 d-10 or 1 d-35 may include some ofthe following functions.

Data transmission function (Transfer of upper layer PDUs)

Sequential delivery function (In-sequence delivery of upper layer PDUs)

Non-sequential delivery function (Out-of-sequence delivery of upperlayer PDUs)

ARQ function (Error correction through ARQ)

Concatenation, segmentation, and reassembly function (Concatenation,segmentation and reassembly of RLC SDUs)

Re-segmentation function (Re-segmentation of RLC data PDUs)

Reordering function (Reordering of RLC data PDUs)

Duplicate detection function (Duplicate detection)

Error detection function (Protocol error detection)

RLC SDU deletion function (RLC SDU discard)

RLC re-establishment function (RLC re-establishment)

The sequential delivery function (In-sequence delivery) of the NR RLCdevice is a function of sequentially transferring RLC SDUs received froma lower layer to a higher layer, and may include, when one original RLCSDU is divided into a plurality of RLC SDUs and then received, afunction of reassembling and transmitting the RLC SDUs, a function ofreordering the received RLC PDUs based on an RLC SN or a PDCP SN, afunction of recording RLC SDUs lost due to the reordering, a function ofreporting statuses of the lost RLC SDUs to a transmitting side, afunction of making a request for retransmitting the lost RLC SDUs, ifthere is a lost RLC SDU, a function of sequentially transferring onlyRLC SDUs preceding the lost RLC SDU to the higher layer if apredetermined timer expires even though there is a lost RLC SDU, afunction of sequentially transferring all RLC SDUs received before thetimer starts to the higher layer, or, if a predetermined timer expireseven though there is a lost RLC SDU, a function of sequentiallytransferring all RLC SDUs received up to that point in time to thehigher layer. Further, the NR RLC device may process the RLC PDUssequentially according to a reception order thereof (according to anarrival order regardless of a serial number or a SN) and transfer theRLC PDUs to the PDCP device regardless of the sequence thereof(out-of-sequence delivery). In the case of segments, the NR RLC devicemay receive segments which are stored in the buffer or will be receivedin the future, reconfigure the segments to be one RLC PDU, process theRLC PDU, and then transmit the same to the PDCP device. The NR RLC layermay not include a concatenation function, and the function may beperformed by the NR MAC layer or may be replaced with a multiplexingfunction of the NR MAC layer.

The non-sequential function (Out-of-sequence delivery) of the NR RLCdevice is a function of transferring RLC SDUs received from a lowerlayer directly to a higher layer regardless of the sequence of the RLCSDUs, and may include, when one original RLC SDU is divided into aplurality of RLC SDUs and then received, a function of reassembling andtransmitting the RLC PDUs and a function of storing RLC SNs or PDCP SNsof the received RLC PDUs, reordering the RLC PDUs, and recording lostRLC PDUs.

The NR MAC 1 d-15 and 1 d-30 may be connected to a plurality of NR RLClayer devices configured in one device, and the main functions of the NRMAC may include some of the following functions.

Mapping function (Mapping between logical channels and transportchannels)

Multiplexing and demultiplexing function (Multiplexing/demultiplexing ofMAC SDUs)

Scheduling information report function (Scheduling informationreporting)

HARQ function (Error correction through HARQ)

Logical channel priority control function (Priority handling betweenlogical channels of one UE)

UE priority control function (Priority handling between UEs by means ofdynamic scheduling)

MBMS service identification function (MBMS service identification)

Transport format selection function (Transport format selection)

Padding function (Padding)

The PHY layers 1 d-20 and 1 d-25 perform an operation for channel-codingand modulating higher-layer data to generate an OFDM symbol andtransmitting the OFDM symbol through a radio channel or demodulating andchannel-decoding the OFDM symbol received through the radio channel andtransmitting the demodulated and channel-decoded OFDM symbol to thehigher layer.

Although not illustrated, there is a radio resource control (RRC) layerabove the PDCP layer of each of the UE and the NR gNB, and the RRC layermay transmit and receive an access- and measurement-relatedconfiguration control message in order to control radio resources.

When activation/deactivation of a semi-persistent sounding referencesignal (SP SRS) in a next-generation mobile communication system isindicated, a beam through which the corresponding SP SRS is transmitted,that is, a QCLed beam, may be indicated, and thus the UE and the NR gNBperform an operation of transmitting and receiving the SP SRS throughbeams radiated in appropriate directions in the disclosure. Thefollowing drawing illustrates an operation of generally performingactivation and deactivation of the SP SRS through a MAC CE.

FIG. 1E illustrates an operation of activating/deactivating asemi-persistent sounding reference signal according to an embodiment ofthe disclosure.

Referring to FIG. 1E, a UE 1 e-01 in an idle mode (or RRC IDLE) maydiscover an appropriate cell and camp on the corresponding gNB1 e-03 atoperation 1 e-05, and may access the gNB 1 e-03 for the reason ofgeneration of data to be transmitted at operation 1 e-10. In the idlemode, the UE 1 e-01 is not connected to the network to save power, sothe UE 1 e-01 cannot transmit data. In order to transmit data, the UE 1e-01 is required to transition to a connected mode (RRC CONNECTED).“Camping on” means that the UE 1 e-01 is receiving a paging message inorder to determine whether data is received through downlink whilestaying in the corresponding cell. When the UE 1 e-01 successfullyperforms access to the gNB 1 e-03, the UE 1 e-01 transitions to theconnected mode (RRC CONNECTED) and the UE 1 e-01 in the connected modecan transmit and receive data to and from the gNB 1 e-03 at operation 1e-15.

In the RRC-connected state, the gNB 1 e-03 transmits configurationinformation (SRS-Config) related to a sounding reference signal (SRS) tothe UE 1 e-01 through an RRC message at operation 1 e-20. The RRCmessage contains configuration information of a plurality of SRSresource sets. The SRS resource set may be configured to be at least oneof periodic, semi-persistent, and aperiodic, and a plurality of SRSresources may be configured in the corresponding SRS resource set. TheSRS resources are included in the SRS resource set and thus follow theconfigured transmission type (periodic, semi-periodic, or aperiodic).Parameters for SRS transmission may be provided to each SRS resourcethrough RRC configuration (SRS-Resource), and particularly, a referencesignal indicating spatial relation for actually transmitting thecorresponding SRS may be indicated. The indicator may select one of asynchronization signal block (SSB), a channel stateinformation-reference signal (CSI-RS), and an SRS fromspatialRelationInfo, and may indicate the reference signal beam at whichthe SRS is actually QCLed by adding an index of the corresponding type.This may be a method of specifying the type and direction of the beamthrough which the corresponding SRS is actually transmitted.

More particularly, at operation 1 e-25, the gNB may indicate activationand deactivation of the SRS resource set in which the SP SRS isconfigured through the MAC CE. The MAC CE includes a serving cell ID inwhich the SRS resource set is configured, a BWP ID, an SRS resource setID, and an indicator for indicating whether there is a supplementaryuplink (SUL), and also includes type and index information of the QCLedreference signal. The disclosure proposes an operation of specifying theserving cell indicating the QCLed reference signal and the BWP ID. Tothis end, the UE 1 e-01 may transmit the SRS for the SRS resource setconfigured in the current serving cell through a resource type and abeam direction configured in another neighboring cell, and the gNB 1e-03 may more flexibly transmit and receive the SRS. At operation 1e-30, the UE 1 e-01 transmits the SP SRS configured by the gNB 1 e-03.The gNB 1 e-03 sets the SP SRS MAC CE as deactivated and transmits theSP SRS MAC CE to the UE 1 e-01 in order to stop transmission of thecorresponding SP SRS at an appropriate time after receiving the SP SRSin 1 e-35. Upon receiving the MAC CE from the gNB, the UE 1 e-03 stopstransmitting corresponding SP SRS resources at operation 1 e-40.

FIG. 1F illustrates MAC CE format method 1 of configuring a referencesignal of a neighboring cell as a beam of a semi-persistent soundingreference signal according to an embodiment of the disclosure.

Referring to FIG. 1F, a method of configuring a reference signal of aneighboring cell as a beam of a semi-persistent sounding referencesignal is illustrated by expanding the SP SRS activation/deactivationMCE CE of the related art. For example, an index of the QCLedneighboring cell and an indicator for indicating a BWP ID areadditionally provided only when SRS transmission is QCLed. The structureof the SP SRS activation/deactivation MAC CE provided by the current NRMAC standard and a newly added field will be described.

In Solution 1 without “U” field (1 f-a), with respect to SRS resourcesincluded in the indicated SP SRS resource set, the first method of therelated art of expanding the SP SRS MAC CE provides cross-carrierindication to every QCLed reference resource. “Cross-carrier indication”means that the QCLed reference signal for the SRS resources indicated bythe MAC CE is directed to a neighboring serving cell, rather than to thecurrent serving cell. In 1 f-05, there is an A/D field indicatingactivation or deactivation of the SP SRS, and indicators indicating theserving cell in which the corresponding SP SRS resource set isconfigured and a BWP ID are included. In 1 f-10, an identifierindicating an ID of the SP SRS resource set may be included, and a SULindicator and a newly defined “C” field may be used, which indicateswhether cross-carrier indication is configured for the SRS resources.When the corresponding field is set to “1”, fields indicating a servingcell ID and a BWP ID of the spatial relation reference signal are added,like in 1 f-25 and 1 f-30. When the corresponding field is set to “0”,the additional fields, such as 1 f-25 and 1 f-30, are omitted. In 1 f-15and 1 f-20, a type and an indicator for indicating the QCLed referencesignal for the SRS resources are included. The type of the spatialrelation reference signal may be one of SSB, CSI-RS, and SRS, and a1-bit type field and a 1-bit most significant bit of a resource ID areused to indicate the signal type. Further, the resource ID is apredetermined type of reference signal ID.

When SRS resources in the SP SRS resource set have a common valuebecause the number of cross-carrier indication serving cells is one, thesecond method of the related art of expanding the SP SRS MAC CE adds afield indicating the same and corresponding information, as in solution1 with “U” field (1 f-b). Compared to solution 1 without “U” field 1f-a, it is possible to reduce the overhead of a repeated octet for aplurality of cross carrier indications through a new 1-bit field. In 1f-35, there is an A/D field indicating activation or deactivation of theSP SRS and indicators indicating a serving cell in which thecorresponding SP SRS resource set is configured and a BWP ID isincluded. At operation 1 f-40, an indicator for indicating the ID of theSP SRS resource set is included, and a “C” field may be used, and thusoperation is performed in the same way as described above. For example,when the corresponding field is set to “1”, fields indicating a servingcell ID and a BWP ID of the spatial relation reference signal are added,like in 1 f-25, 1 f-30, and if-55. When the corresponding field is setto “0”, the additional fields, such as 1 f-25 and 1 f-30 are omitted.Further, a newly defined “U” field may exist in the octet 1 f-40 and maybe used in the case in which a serving cell and a BWP ID of a pluralityof reference signals QCLed only when the “C” field is set to “1” areindicated as a neighboring common serving cell and a BWP. For example,when the “U” field is set to “1”, as illustrated in 1 f-55, 1 byte ofcross-carrier indication information is added. When the “U” field is setto “0”, the corresponding cross-carrier indication information may beadded to every QCLed reference signal, as in solution 1 without “U”field 1 f-a. In 1 f-45 and 1 f-50, a type and an indicator forindicating the QCLed reference signal for the SRS resources areincluded. The type of the spatial relation reference signal may be oneof SSB, CSI-RS, and SRS, and a 1-bit type field and a 1-bit MSB of aresource ID are used to indicate the signal type. Further, the resourceID is a predetermined type of reference signal ID. 1 f-55 includesindicators indicating the serving cell and the BWP in which thereference signals indicated in 1 f-45 and 1 f-50 are configured.

FIG. 1G illustrates MAC CE format method 2 of configuring a referencesignal of a neighboring cell as a beam of a semi-persistent soundingreference signal according to an embodiment of the disclosure.

Referring to FIG. 1G, a method of using a new MAC CE is illustrated forconfiguring a reference signal of a neighboring cell as a beam of asemi-persistent sounding reference signal separately from the SP SRSactivation/deactivation MAC CE of the related art. For example, onlywhen the SRS transmission is QCLed, the newly proposed MAC CE(hereinafter referred to as an SP SRS activation/deactivationcross-carrier indication MAC CE) is used without using the previous SPSRS activation/deactivation MAC CE. In the MAC CE, an index of the QCLedneighboring cell and an indicator for indicating a BWP ID are provided.Basically, since the previous SP SRS activation/deactivation MAC CE isused without change, a MAC CE distinguished therefrom through a logicalchannel identity (LCID) is separately needed, and the structure thereofwill be described below.

In 1 g-05, there is an A/D field indicating activation or deactivationof the SP SRS, and indicators indicating a serving cell in which thecorresponding SP SRS resource set is configured and a BWP ID areincluded. In 1 g-10, an identifier indicating the ID of the SP SRSresource set is included and an SUL indicator is included. Thereafter,QCLed beam information for the SP SRS resources included in the SRSresources may be included in the indicated SP SRS resource set.Cross-carrier serving cell ID and BWP ID information of thecorresponding QCLed beam are included in 1 g-15 and a type and an indexof the corresponding beam are included in 1 g-20. 1 g-15 and 1 g-20exist as a set of the configuration for one reference signal.

Thereafter, information on the QCLed reference signal like 1 g-15 and 1g-20 are added by the number (M) of SP SRS resources included in the SPSRS resource set. In Solution 2 field (1 g-a), as in 1 g-25 and 1 g-30,M pieces of set information are added to the corresponding MAC CE. Thetype of the spatial relation reference signal of 1 g-20 and 1 g-30 maybe one of SSB, CSI-RS, and SRS, and a type field of 1 bit and the MSB of1 bit of a resource ID are used to indicate the signal type. Further,the resource ID is a predetermined type of reference signal ID.

FIG. 1H illustrates MAC CE format method 3 of configuring a referencesignal of a neighboring cell as a beam of a semi-persistent soundingreference signal according to an embodiment of the disclosure.

Referring to FIG. 1H, a method of using a new MAC CE is illustrated forconfiguring a reference signal of a neighboring cell as a beam of asemi-persistent sounding reference signal separately from the SP SRSactivation/deactivation MAC CE of the related art. For example, onlywhen the SRS transmission is QCLed, the newly proposed MAC CE(hereinafter referred to as an SP SRS activation/deactivationcross-carrier indication MAC CE) is used, rather than using the previousSP SRS activation/deactivation MAC CE. The difference from the MAC CEformat method 2 is that the MAC CE format method 3 provides thecorresponding configuration through RRC, and an index is indicated bythe MAC CE without including information indicating the QCLed beam intothe MAC CE. Basically, since the previous SP SRS activation/deactivationMAC CE is used without change, a separate MAC CE distinguished therefromthrough an LCID is needed, and the structure thereof will be describedbelow.

In 1 h-05, there is an A/D field indicating activation or deactivationof the SP SRS, and indicators indicating the serving cell in which thecorresponding SP SRS resource set is configured and a BWP ID areincluded. In 1 h-10, an identifier indicating the ID of the SP SRSresource set is included, and an SUL indicator is included. Thereafter,QCLed beam information for the SP SRS resources included in the SRSresources may be included in the indicated SP SRS resource set. InSolution 3: option 1 field (1 h-a), the distinguishing feature of theembodiment is that QCLed reference signal information and cross-carrierindication are indicated through a spatial relation info ID in 1 h-15and 1 h-20. For example, all of the serving cell ID of the QCLedreference signal, the BWP IP, and the reference signal type and ID areconfigured for SP SRS resources through RRC configuration, which isindicated by a spatial relation inform ID. It is assumed that the sizeof the corresponding spatial relation info may be configured as aparticular constant and may be configured as 16 in the embodiment. Thespatial relation info can be configured such that a plurality of piecesof spatial relation info is included in 1 octet like in 1 h-b in orderto reduce the size of the MAC CE according to the size of the spatialrelation info, although the corresponding information is the same.

FIG. 1I is a block diagram illustrating an internal structure of a UEaccording to an embodiment of the disclosure.

Referring to FIG. 1I, the UE includes a radio-frequency (RF) processingunit 1 i-10, a baseband processing unit 1 i-20, a storage unit 1 i-30,and a controller 1 i-40.

The RF processing unit 1 i-10 performs a function for transmitting andreceiving a signal through a wireless channel, such as band conversionand amplification of a signal. For example, the RF processing unit 1i-10 up-converts a baseband signal provided from the baseband processingunit 1 i-20 into an RF band signal, transmits the RF band signal throughan antenna, and then down-converts the RF band signal received throughthe antenna into a baseband signal. For example, the RF processing unit1 i-10 may include a transmission filter, a reception filter, anamplifier, a mixer, an oscillator, a digital-to-analog convertor (DAC),an analog-to-digital convertor (ADC), and the like. Although FIG. 1Iillustrates only one antenna, the UE may include a plurality ofantennas. The RF processing unit 1 i-10 may include a plurality of RFchains. Moreover, the RF processing unit 1 i-10 may perform beamforming.For the beamforming, the RF processing unit 1 i-10 may control a phaseand a size of each signal transmitted/received through a plurality ofantennas or antenna elements. The RF processing unit may perform MIMOand receive a plurality of layers when performing the MIMO operation.

The baseband processing unit 1 i-20 performs a function for conversionbetween a baseband signal and a bitstream according to a physical-layerstandard of the system. For example, when transmitting data, thebaseband processing unit 1 i-20 generates complex symbols by encodingand modulating a transmission bitstream. Further, when receiving data,the baseband processing unit 1 i-20 reconstructs a reception bitstreamby demodulating and decoding a baseband signal provided from the RFprocessing unit 1 i-10. For example, in an OFDM scheme, whentransmitting data, the baseband processing unit 1 i-20 generates complexsymbols by encoding and modulating a transmission bitstream, maps thecomplex symbols to subcarriers, and then configures OFDM symbols throughan inverse fast Fourier transform (IFFT) operation and a cyclic prefix(CP) insertion. Further, when data is received, the baseband processingunit 1 i-20 divides the baseband signal provided from the RF processingunit 1 i-10 in units of OFDM symbols, reconstructs the signals mapped tothe subcarriers through a fast Fourier transform (FFT) operation, andthen reconstructs a reception bitstream through demodulation anddecoding.

The baseband processing unit 1 i-20 and the RF processing unit 1 i-10transmit and receive signals as described above. Accordingly, thebaseband processing unit 1 i-20 and the RF processing unit 1 i-10 may beembodied as a transmitter, a receiver, a transceiver, or a communicationunit. Further, at least one of the baseband processing unit 1 i-20 andthe RF processing unit 1 i-10 may include a plurality of communicationmodules for supporting a plurality of different radio accesstechnologies. In addition, at least one of the baseband processing unit1 i-20 and the RF processing unit 1 i-10 may include differentcommunication modules for processing signals in different frequencybands. For example, the different communication standards may include awireless LAN (for example, IEEE 802.11) and a cellular network (forexample, LTE). Further, the different frequency bands may include asuper-high frequency (SHF) (for example, 2.NRHz, NRhz) band and amillimeter (mm) wave (for example, 60 GHz) band.

The storage unit 1 i-30 stores data, such as a basic program, anapplication, and setting information for the operation of the UE.Particularly, the storage unit 1 i-30 may store information related to asecond access node performing wireless communication through a secondradio access technology. The storage unit 1 i-30 provides stored data inresponse to a request from the controller 1 i-40.

The controller 1 i-40 controls the overall operation of the UE. Forexample, the controller 1 i-40 transmits and receives a signal throughthe baseband processing unit 1 i-20 and the RF processing unit 1 i-10.The controller 1 i-40 records data in the storage unit 1 i-30 and readsthe data. To this end, the controller 1 i-40 may include at least oneprocessor. For example, the controller 1 i-40 may include acommunications processor (CP) that performs control for communication,and an application processor (AP) that controls higher layers, such asan application layer. The controller 1 i-40 may include amulti-connection processing unit 1 i-42 for processing information whichis a reference for determining whether or not to allow multipleconnections to the UE.

FIG. 1J is a block diagram illustrating a configuration of an NR NBaccording to an embodiment of the disclosure.

Referring to FIG. 1J, the NR NB includes an RF processing unit 1 j-10, abaseband processing unit 1 j-20, a backhaul communication unit 1 j-30, astorage unit 1 j-40, and a controller 1 j-50.

The RF processing unit 1 j-10 performs a function for transmitting andreceiving a signal through a radio channel, such as band conversion andamplification of a signal. For example, the RF processing unit 1 j-10up-converts a baseband signal provided from the baseband processing unit1 j-20 into an RF band signal, transmits the RF band signal through anantenna, and then down-converts the RF band signal received through theantenna into a baseband signal. For example, the RF processing unit 1j-10 may include a transmission filter, a reception filter, anamplifier, a mixer, an oscillator, a DAC, and an ADC. Although FIG. 1Jillustrates only one antenna, the first access node may include aplurality of antennas. Further, the RF processing unit 1 j-10 mayinclude a plurality of RF chains. The RF processing unit 1 j-10 mayperform beamforming. For the beamforming, the RF processing unit 1 j-10may control a phase and a size of each of the signals transmitted andreceived through a plurality of antennas or antenna elements. The RFprocessing unit may perform a downlink MIMO operation by transmittingone or more layers.

The baseband processing unit 1 j-20 performs a function of conversionbetween a baseband signal and a bitstream according to a physical-layerstandard of the first radio access technology. For example, whentransmitting data, the baseband processing unit 1 j-20 generates complexsymbols by encoding and modulating a transmission bitstream. Further,when receiving data, the baseband processing unit 1 j-20 reconstructs areception bitstream by demodulating and decoding a baseband signalprovided from the RF processing unit 1 j-10. For example, in an OFDMscheme, when transmitting data, the baseband processing unit 1 j-20 maygenerate complex symbols by encoding and modulating the transmissionbitstream, map the complex symbols to subcarriers, and then configureOFDM symbols through an IFFT operation and CP insertion. In addition,when receiving data, the baseband processing unit 1 j-20 divides abaseband signal provided from the RF processing unit 1 j-10 in units ofOFDM symbols, recovers signals mapped with subcarriers through an FFToperation, and then recovers a reception bitstream through demodulationand decoding. The baseband processing unit 1 j-20 and the RF processingunit 1 j-10 transmit and receive signals as described above.Accordingly, the baseband processing unit 1 j-20 and the RF processingunit 1 j-10 may be embodied as a transmitter, a receiver, a transceiver,a communication unit, or a wireless communication unit.

The backhaul communication unit 1 j-30 provides an interface forcommunicating with other nodes within the network. For example, thebackhaul communication unit 1 j-30 converts a bitstream transmitted toanother node, for example, a secondary eNB (SeNB) or a CN from a mastereNB (MeNB), into a physical signal and converts a physical signalreceived from the other node into the bitstream.

The storage unit 1 j-40 stores data, such as a basic program, anapplication, or configuration information for the operation of the MeNB.Particularly, the storage unit 1 j-40 may store information on a bearerallocated to the access UE and a measurement result reported by theaccessed UE. Further, the storage unit 1 j-40 may store informationwhich is a reference for determining whether or not to allow multipleconnections to the UE. In addition, the storage unit 1 j-40 providesstored data in response to a request from the controller 1 j-50.

The controller 1 j-50 controls the overall operation of the MeNB. Forexample, the controller 1 j-50 transmits and receives a signal throughthe baseband processing unit 1 j-20 and the RF processing unit 1 j-10 orthrough the backhaul communication unit 1 j-30. Further, the controller1 j-50 records data in the storage unit 1 j-40 and reads the data. Tothis end, the controller 1 j-50 may include at least one processor.Further, the controller 1 j-50 may include a multi-connection processingunit 1 j-52 for processing information which is a reference fordetermining whether or not to allow multiple connections to the UE.

Second Embodiment

Hereinafter, the operating principle of the disclosure will be describedwith reference to the accompanying drawings. In describing thedisclosure below, a detailed description of related known configurationsor functions incorporated herein will be omitted when it is determinedthat the detailed description thereof may unnecessarily obscure thesubject matter of the disclosure. The terms which will be used below areterms defined in consideration of the functions in the disclosure, andmay be different according to users, intentions of the users, orcustoms. Therefore, the definitions of the terms should be made based onthe contents throughout the specification. In the following description,terms for identifying an access node, terms referring to networkentities, terms referring to messages, terms referring to interfacesbetween network entities, and terms referring to various pieces ofidentification information are used for convenience of description.Therefore, the disclosure is not limited by the terminologies providedbelow, and other terms that indicate subjects having equivalenttechnical meanings may be used.

For convenience of description, the disclosure uses terms and namesdefined in a 3rd-generation partnership project, 3GPP LTE standard orterms and names changed on the basis thereof. However, the disclosure isnot limited to the terms and names, and may be equally applied to asystem according to another standard.

FIG. 2A illustrates a structure of a next-generation mobilecommunication system according to an embodiment of the disclosure.

Referring to FIG. 2A, a RAN of the next-generation mobile communicationsystem includes a next-generation eNB (new radio node B, hereinafter,referred to as NR gNB or NR NB) 2 a-10 and a new radio core network (NRCN) 2 a-05, as illustrated in FIG. 2A. A user terminal (new radio userequipment, hereinafter, referred to as a NR UE, a UE, or a terminal) 2a-15 accesses an external network through the NR gNB 2 a-10 and the NRCN 2 a-05.

In FIG. 2A, the NR gNB 2 a-10 included in network 2 a-20 corresponds toan eNB of an LTE system of the related art. The NR gNB 2 a-10 may beconnected to the NR UE 2 a-15 through a radio channel and may providebetter service than a node B of the related art. Since all user trafficis served through a shared channel in the next-generation mobilecommunication system, a device for collecting and scheduling statusinformation of buffer statuses, available transmission power statuses,and channel statuses of UEs is required, which corresponds to the NR gNB2 a-10. One NR gNB 2 a-10 generally controls a plurality of cells. TheNR NB may have a bandwidth wider than the maximum bandwidth of therelated art in order to implement super-high-speed data transmissioncompared to LTE of the related art, may apply OFDM through radio accesstechnology, and may further apply beamforming technology. Further, anAMC scheme of determining a modulation scheme and a channel coding rateis applied depending on the channel status of the UE. The NR CN 2 a-05performs a function of supporting mobility, configuring a bearer, andconfiguring QoS. The NR CN 2 a-05 serves to perform a function ofmanaging the mobility of the UE and various control functions and isconnected to a plurality of NR NBs. Further, the next-generation mobilecommunication system may be linked to the LTE system of the related art,and the NR CN 2 a-05 may be connected to an MME 2 a-25 through a networkinterface. The MME 2 a-25 may be connected to an eNB 2 a-30, which is aneNB of the related art.

FIG. 2B illustrates a wireless protocol structure of a next-generationmobile communication system according to an embodiment of thedisclosure.

Referring to FIG. 2B, the wireless protocol of the next-generationmobile communication system includes NR PDCPs 2 b-05 and 2 b-40, NR RLCs2 b-10 and 2 b-35, and NR MACs 2 b-15 and 2 b-30 in the UE and the NRgNB. The main functions of the NR PDCP 2 b-05 or 2 b-40 may include someof the following functions.

Header compression and decompression function ((Header compression anddecompression: ROHC only)

User data transmission function

Sequential delivery function (In-sequence delivery of upper-layer PDUs)

Reordering function (PDCP PDU reordering for reception)

Duplicate detection function (Duplicate detection of lower layer SDUs)

Retransmission function (Retransmission of PDCP SDUs)

Ciphering and deciphering function (Ciphering and deciphering)

Timer-based SDU removal function (Timer-based SDU discard in uplink)

The reordering function of the NR PDCP device is a function ofsequentially reordering PDCP PDUs received from a lower layer based on aPDCP SN, and may include a function of sequentially transferring thereordered data to a higher layer, a function of recording PDCP PDUs lostdue to the reordering, a function of reporting statuses of the lost PDCPPDUs to a transmitting side, and a function of making a request forretransmitting the lost PDCP PDUs.

The main functions of the NR RLC 2 b-10 or 2 b-35 may include some ofthe following functions.

Data transmission function (Transfer of upper layer PDUs)

Sequential delivery function (In-sequence delivery of upper layer PDUs)

Non-sequential delivery function (Out-of-sequence delivery of upperlayer PDUs)

ARQ function (Error correction through ARQ)

Concatenation, segmentation, and reassembly function (Concatenation,segmentation and reassembly of RLC SDUs)

Re-segmentation function (Re-segmentation of RLC data PDUs)

Reordering function (Reordering of RLC data PDUs)

Duplicate detection function (Duplicate detection)

Error detection function (Protocol error detection)

RLC SDU deletion function (RLC SDU discard)

RLC re-establishment function (RLC re-establishment)

The sequential delivery function (In-sequence delivery) of the NR RLCdevice is a function of sequentially transferring PDCP PDUs receivedfrom a lower layer to a higher layer, and may include, when one originalRLC SDU is divided into a plurality of RLC SDUs and then received, afunction of reassembling and transmitting the RLC SDUs, a function ofreordering the received RLC PDUs based on an RLC SN or a PDCP SN, afunction of recording PDCP PDUs lost due to the reordering, a functionof reporting statuses of the lost PDCP PDUs to a transmitting side, afunction of making a request for retransmitting the lost PDCP PDUs, ifthere is a lost RLC SDU, a function of sequentially transferring onlyRLC SDUs preceding the lost RLC SDU to the higher layer, if apredetermined timer expires even though there is a lost RLC SDU, afunction of sequentially transferring all RLC SDUs received before thetimer starts to the higher layer, or if a predetermined timer expireseven though there is a lost RLC SDU, a function of sequentiallytransferring all RLC SDUs received up to that point in time to thehigher layer. Further, the NR RLC device may process the RLC PDUssequentially in a reception order thereof (according to an arrival orderregardless of a serial number or a SN) and may transfer the RLC PDUs tothe PDCP device regardless of the sequence thereof (out-of-sequencedelivery). In the case of segments, the NR RLC device may receivesegments which are stored in the buffer or will be received in thefuture, reconfigure the segments to be one RLC PDU, process the RLC PDU,and then transmit the same to the PDCP device. The NR RLC layer may notinclude a concatenation function, and the function may be performed bythe NR MAC layer, or may be replaced with a multiplexing function of theNR MAC layer.

The non-sequential function (Out-of-sequence delivery) of the NR RLCdevice is a function of transferring RLC SDUs received from a lowerlayer directly to a higher layer regardless of the sequence of the RLCSDUs, and may include, when one original RLC SDU is divided into aplurality of RLC SDUs and then received, a function of reassembling andtransmitting the RLC PDUs and a function of storing RLC SNs or PDCP SNsof the received RLC PDUs, reordering the RLC PDUs, and recording lostRLC PDUs.

The NR MAC 2 b-15 and 2 b-30 may be connected to a plurality of NR RLClayer devices configured in one device, and the main functions of the NRMAC may include some of the following functions.

Mapping function (Mapping between logical channels and transportchannels)

Multiplexing and demultiplexing function (Multiplexing/demultiplexing ofMAC SDUs)

Scheduling information report function (Scheduling informationreporting)

HARQ function (Error correction through HARQ)

Logical channel priority control function (Priority handling betweenlogical channels of one UE)

UE priority control function (Priority handling between UEs by means ofdynamic scheduling)

MBMS service identification function (MBMS service identification)

Transport format selection function (Transport format selection)

Padding function (Padding)

The PHY layers 2 b-20 and 2 b-25 perform an operation for channel-codingand modulating higher-layer data to generate an OFDM symbol andtransmitting the OFDM symbol through a radio channel or demodulating andchannel-decoding the OFDM symbol received through the radio channel andtransmitting the demodulated and channel-decoded OFDM symbol to thehigher layer.

Although not illustrated, there is a RRC layer above the PDCP layer ofeach of the UE and the NR gNB, and the RRC layer may transmit andreceive an access- and measurement-related configuration control messageto control radio resources.

FIG. 2C schematically illustrates an operation from a CN to a UE forprocessing a QoS in an NR system according to an embodiment of thedisclosure.

Referring to FIG. 2C, a method of providing end-to-end service for eachQoS flow in all operations for supporting an IP service to a UE 2 c-05,an NR node (gNB) 2 c-10, an NG-UP 2 c-15, and an Internet peer 2 c-20 inthe NR system. At operation 2 c-25, for the peer 2 c-20 providing anInternet service in which a packet data network (PDN) connection isestablished, that is, for one PDN, a PDU session may be configured, andat operations 2 c-45, 2 c-50, and 2 c-55, QoS flows may be transmittedthrough one tunnel up to the NG-CN 2 c-15. In the NG-CN 2 c-15, one ormore PDU sessions may be configured up to the UE, in which case PDUsessions are independently configured as illustrated in the drawing. Atoperation 2 c-30, the gNB 2 c-10 receives a packet from the NG-CN 2 c-15and the packet is transmitted through the QoS flow to which the packetbelongs. For example, the packet is transmitted according to the ruleunder which the IP flow is mapped to the QoS flow. At operations 2 c-35and 2 c-40, the gNB 2 c-10 identifies the DRB to which a particular QoSflow is mapped, and may map and transmit the QoS flow to the UE throughthe particular DRB according to a mapping rule. At the operation, thegNB 2 c-10 may determine the DRB to which the particular QoS flow ismapped.

FIGS. 2DA and 2DB illustrate new functions for handling a QoS in the NRsystem according to an embodiment of the disclosure.

Referring to FIGS. 2DA and 2DB, in the NR system, a user traffictransmission path should be configured according to services requiringdifferent quality of service (QoS), that is, the QoS requirements or IPflow should be controlled according to each service. The NR CN mayconfigure a plurality of packet data unit (PDU) sessions, and each PDUsession may include a plurality of IP flows. The NR gNB may map aplurality of QoS flows to a plurality of data radio bearers (DRBs) andsimultaneously configure the same. For example, since a plurality of QoSflows 2 d-01, 2 d-02, and 2 d-03 may be mapped to the same DRB ordifferent DRBs 2 d-10, 2 d-15, and 2 d-20 in downlink, it is required tomark a QoS flow ID in a downlink packet in order to distinguish betweenthe QoS flows. Alternatively, DRB mapping may be explicitly configuredthrough an RRC control message. Such a function is not included in theLTE PDCP protocol of the related art, so that a new protocol (servicedata access protocol (SDAP) 2 d-05, 2 d-40, 2 d-50, or 2 d-85) should beintroduced, or a function of performing the new function should be addedto the PDCP. Further, the marking allows the UE to implement areflective QoS for uplink. The reflective QoS refers to a mapping methodof allowing the UE to perform uplink transmission through a DRB throughwhich a downlink packet having a particular flow ID transmitted by thegNB is transmitted, and in order to indicate the reflective QoS, areflective QoS indicator (RQI) of 1 bit and a reflective QoS flow to DRBmapping indication (RDI) of 1 bit may be included in an SDAP header.

For example, a plurality of QoS flows 2 d-86, 2 d-87, and 2 d-88 may bemapped to the same DRB or different DRBs 2 d-70, 2 d-75, and 2 d-80 inuplink. Explicitly marking the QoS flow ID in the downlink packetcorresponds to a simple method by which an access stratum (AS) of the UEprovides the information to a NAS of the UE. A method of mapping IPflows to DRBs in downlink may be performed through two operations below.

1. NAS level mapping (RQI): IP flow→QoS flow

2. AS level mapping (RDI): QoS flow→DRB

In downlink reception of the UE, QoS flow mapping information and theexistence or nonexistence of the reflective QoS operation may bedetected for each DRB 2 d-25, 2 d-30, or 2 d-35 and the correspondinginformation of QoS flows 2 d-41, 2 d-42, and 2 d-43 may be transmittedto the NAS. For example, when the RQI and the RDI are set to “1” in theSDAP header of the received data packet, it means that the NAS and ASmapping rules have been updated, so the UE may update the mapping ruleand transmit the uplink packet according thereto. For example,two-operation mapping may also be used for uplink. First, IP flows aremapped to QoS flows through NAS signaling, and QoS flows 2 d-45, 2 d-46,and 2 d-47 are mapped to determined DRBs 2 d-55, 2 d-60, and 2 d-65,respectively, in the AS. The UE may mark a QoS flow ID in the uplinkpacket, or may transmit the packet without marking the QoS flow ID. Thefunction is performed by the SDAP of the UE. When the QoS flow ID ismarked in the uplink packet, the NR gNB marks the QoS flow ID withoutthe uplink traffic flow template (TFT) in the packet through which theinformation is transmitted to NG-U and transmits the packet.

FIGS. 2EA and 2EB illustrate a protocol stack including an SDAP in NRaccording to an embodiment of the disclosure.

Referring to FIGS. 2EA and 2EB, in order to handle a new QoS function ofthe NR system, the following information should be transmitted through aradio interface.

Downlink: QoS flow ID+RQI+RDI

Uplink: QoS flow ID

In NR, an interface for transmitting the new information to a Uu isneeded, and a new protocol for performing the function is defined on thePDCP 2 e-10 layer. The SDAP 2 e-05 is not a DRB-based protocol, andpackets are transmitted according to the configured DRB 2 e-30 mappingrule. For example, IP traffic is generated, and the SDAP 2 e-05 maps theIP flow to the QoS flow ID and then maps the QoS flow ID to the DRB. TheIP traffic includes an IP header and a payload, and the SDAP headers 2e-35, 2 e-40, and 2 e-45 may be located before the IP packet. The PDCP 2e-10 compresses the IP header and adds PDCP headers 2 e-50, 2 e-55, and2 e-60. The RLC 2 e-15 and the MAC 2 e-20 also sequentially add RLCheaders 2 e-65, 2 e-70, and 2 e-75, 2 e-80 and MAC sub-headers 2 e-85and then a MAC header 2 e-90, and then transmit a MAC PDU to the PHY 2e-25.

When the gNB determines to apply a reflective mechanism to the UE(instructs the UE to transmit an uplink packet through a DRB, which isthe same as the DRB through which a QoS flow ID included in a downlinkpacket is transmitted), the gNB inserts the QoS flow ID and a reflectiveQoS indicator (RDI+RQI) into the ADAP 2 e-05 layer of the downlinkpacket and transmits the downlink packet. The SDAP header has a lengthof 1 byte and may include the QoS flow ID (6 bits) and RQI (1 bit)+RDI(1 bit). For example, 64 QoS flows may be transmitted to the SDAPheader, and it is not possible to specify more QoS flows. The disclosureencompasses the hypothetical case of QoS flows larger than 64 QoS flowsin the future, which may be an example of a need of a large number oftransmission control protocol (TCP) connections and connectionconfiguration of user data protocol (UDP) sessions.

During the process, if the gNB transmits all data packets including theQoS flow ID, the operation of updating the mapping rule through the QoSflow ID received by the UE is continuously performed. For example, ifthe RQI bit and the RDI bit of 1 bit are set to “1”, the UE updates theNAS mapping rule and the AS mapping rule under the assumption that eachof the mapping rules of the NAS and the AS is updated, and transmits theuplink data packet according to the corresponding rule. Basically, theNAS reflective QoS is triggered when a mapping rule between the IP flowand the QoS flow is updated in the NR CN, and the AS reflective QoS istriggered when a mapping rule between the QoS flow and the DRB isupdated in the wireless NB.

However, based on signaling between the NR NB and the CN, if the NASmapping rule is updated, the CN configures an RQI bit indicating theupdate in an N3 header of the data packet transmitted to the NR NB andtransmits the data packet. The N3 header is an interface between the CNand the NR NB. If the RQI bit of the N3 header received from the CN isset to “1”, the NR NB sets the RQI bit of the SDAP header to “1” andtransmits the RQI bit to the UE. Alternatively, if the AS mapping ruleis changed even though the RQI bit of the N3 header is set to “0”, theRDI bit of the SDAP header is set to “1” and transmitted to the UE.However, when the operation is performed, the UE should continuouslystore a mapping information table for NAS mapping and AS mapping, andthus the amount of information that the UE is required to store mayincrease, and if the information is not properly managed, confusion dueto overlapping mapping may occur. In order to solve the problem, the UEand the NR CN operate a timer immediately when the NAS reflective QoSrule is applied, and if the data packet to which the corresponding ruleis applied is not received for a preset time, removes configured NASreflective QoS mapping information. For reference, if the data packet towhich the QoS mapping rule is applied is transmitted and received whilethe timer operates, the timer is restarted.

FIG. 2F illustrates a method of fixedly configuring a QoS flow ID havingan extended length according to an embodiment of the disclosure.

Referring to FIG. 2F, 64 QoS flows can be identified through the 6-bitQoS flow IDs of the related art, but there may be a need to indicate anumber of QoS flows larger than 64 QoS flows, which may be an example ofthe need of many TCP connections and connection configuration of UDPsessions. In the method regarding FIG. 2F, the NR NB may fixedlyconfigure and use mapping between the corresponding DRB and the extendedQoS flow ID through RRC configuration. The N3 header, which is theinterface between NR NBs, may support 2-byte QoS flow IDs, and thus, ifthe CN supports the extended QoS flow IDs, a wireless end mayadditionally support 1-byte information of the QoS flow IDs.

A QFI field 2 f-05 may be expressed by 14 bits, generated by adding 8bits to 6 bits, and 2{circumflex over ( )}14 QoS flows may beidentified. The extended 14-bit QFI may always be present once it isconfigured for a particular DRB. This is identical to the solution with6 bit QFI. Alternatively, the QFI may be expressed in a smaller numberof bits than 14 bits, and some of the second octet of the SDAP headermay be expressed by reserved bits. Like the SDAP header of the relatedart, the RAI bit and the RDI bit of 2 f-10 and 2 f-15 are included, andthe data packet of 2 f-20 is located after the SDAP header. As describedabove, by configuring the use of the extended QoS flow IDs to theconfigured DRBs, the corresponding mapping rule is fixedly applied tothe corresponding DRBs.

FIG. 2G illustrates method 1 of dynamically configuring a QoS flow IDhaving an extended length according to an embodiment of the disclosure.

Referring to FIG. 2G, 64 QoS flows can be identified through the 6-bitQoS flow IDs of the related art, but there may be a need to indicate anumber of QoS flows larger than 64 QoS flows, which may be an example ofthe need for many TCP connections and connection configuration of UDPsessions. The N3 header, which is the interface between NR NBs, maysupport 2-byte QoS flow IDs, and thus if the CN supports the extendedQoS flow IDs, a wireless end may additionally support 1-byte informationof the QoS flow IDs. Embodiment 2-2 of the disclosure describes a methodof using the SDAP header including the dynamically extended QoS flowIDs.

A QFI field 2 g-05 may be expressed by 14 bits, generated by adding 8bits to 6 bits, and 2{circumflex over ( )}14 QoS flows may beidentified. The extended 14-bit QFI may be present only when at leastone of the reflective QoS bits are set (case 2 g-B). Otherwise, if bothreflective QoS bits are set to “0”, then there is only one octet headerwith 6-bits set to a dummy value (or all zeroes) (case 2 g-A).Alternatively, the QFI may be expressed using a smaller number of bitsthan 14 bits, and some of the second octet of the SDAP header may beexpressed using reserved bits. Like the SDAP header of the related art,the RQI bit and the RDI bit of 2 g-10 and 2 g-15 are included, and thedata packet is located after the SDAP header. The extended QFI field 2g-20 may be applied to the case in which one of the RQI bit 2 g-25 andthe RDI bit 2 g-30 is set to “1” (case 2 g-B), and the 6-bit QFI isapplied to the case in which both the RQI bit and the RDI bit are set to“0” (case 2 g-A). If the QFI field value is the same as the previouslyapplied QFI field value, the UE already has the corresponding mappingrule, and thus the UE does not need the QFI information if the mappingrule is not updated (the case in which both the RQI bit and the RDI bitare set to “0”). Therefore, in this case, in order to reduce theoverhead of the SDAP header, the 6-bit QFI of the related art is usedwithout the use of the extended 14-bit QFI. Further, in this case, adummy value (or all zeroes) may be included in the 6-bit QFI fieldvalue. This is because the UE does not analyze the QFI value in the casein which both the RQI bit and the RDI bit are set to “0”.

FIG. 2H illustrates method 2 of dynamically configuring a QoS flow IDhaving an extended length according to an embodiment of the disclosure.

Referring to FIG. 2H, 64 QoS flows can be identified through the 6-bitQoS flow IDs of the related art, but there may be a need to indicate anumber of QoS flows larger than 64 QoS flows, which may be an example ofthe need of many TCP connections and connection configuration of UDPsessions. The N3 header, which is the interface between NR NBs, maysupport 2-byte QoS flow IDs, and thus, if the CN supports the extendedQoS flow IDs, a wireless end may additionally support 1-byte informationof the QoS flow IDs. Embodiment 2-3 of the disclosure describes a methodof using the SDAP header including the dynamically extended QoS flowIDs.

A QFI field 2 h-05 may be expressed by 14 bits, generated by adding 8bits to 6 bits, and 2{circumflex over ( )}14 QoS flows may beidentified. The dummy values (or all zeroes) are used when none of thereflective QoS bits are set (case 2 h-A). Moreover, the 6-bits QFI isused when the QoS flow ID value is for range of 0-63 (case 2 h-B), andthe 14-bits QFI is used when the QoS flow ID value is more than 64 (case2 h-C). Alternatively, the QFI may be expressed using a smaller numberof bits than 14 bits, and some of the second octet of the SDAP headermay be expressed using reserved bits. Like the SDAP header of therelated art, the RQI bit and the RDI bit of 2 g-10 and 2 g-15 areincluded, and the data packet is located after the SDAP header. Theextended QFI field 2 h-35 may be applied to the case in which the QoSflow IDs (i.e., RQI bit 2 h-40 and the RDI bit 2 h-45) that the NR NBapplies are larger than 64 (case 2 h-C) and the 6-bit QFI 2 h-20 isapplied to the case in which the number of QoS flow IDs (i.e., RQI bit 2h-25 and the RDI bit 2 h-30) that the NR NB allocates is smaller than 63(case 2 h-B). Further, when both the RQI bit 2 h-10 and the RDI bit 2h-15 are set to “0” (case 2 h-A), the 6-bit QFI is applied. If the QFIfield value is the same as the previously applied QFI field value, theUE already has the corresponding mapping rule, and thus the UE does notneed the QFI information if the mapping rule is not updated (the case inwhich both the RQI bit and the RDI bit are set to “0”). Therefore, inthis case, in order to reduce the overhead of the SDAP header, the 6-bitQFI of the related art is used, rather than using the extended 14-bitQFI. Further, in this case, a dummy value (or all zeroes) may beincluded in the 6-bit QFI field value. This is because the UE does notanalyze the QFI value in the case in which both the RQI bit and the RDIbit are set to “0”.

FIG. 2I illustrates an overall QoS processing operation to which a QoSmapping rule between a CN and the UE is applied.

Referring to FIG. 2I, the UE camps on a serving cell at operation 2i-05, configures the RRC connection to the corresponding cell, andtransitions to the connected mode at operation 2 i-10. At operation 2i-15, the UE receives information on whether the CN supports the NASreflective QoS operation and NAS mapping timer information from the NRCN and receives information on whether the SDAP header (RQI, RDI, andQoS flow ID) is used from the RRC message of the gNB through SDAPconfiguration. The message may be simultaneously given through RRC, ormay be received through an RRC message separately from the NAS. The NASmapping timer may be a timer indicating how long the CN and the UE canstore the QoS mapping rule for a particular NAS IP packet, and if thetimer expires, the corresponding mapping information is deleted. Atoperation 2 i-20, the CN indicates whether to use the extended 14-bitQFI to the gNB. The information may be transmitted along with the SDAPconfiguration information at operation 2 i-15. Further, the informationmay be indicated for each PDN session. Thereafter, the gNB may know thatthe NR CN uses the extended QFI and may then indicate the extended QFIto the UE through the methods with respect to FIGS. 2F, 2G, and 2H ofthe disclosure.

At operation 2 i-25, the CN supporting the NAS reflective QoS operationidentifies whether NAS reflective QoS mapping (mapping between the IPflow and the QoS flow) is updated for the IP packet to be transmitted tothe UE, and if an update is needed, set the RQI of the N3 header of theIP packet to “1” and transmit the IP packet to the gNB. Simultaneouslywith the operation, the CN executes a NAS mapping timer at operation 2i-30. The gNB checks the RQI bit of the N3 header of the receivedpacket, and if the RQI bit is set to “1”, identifies whether the APmapping rule is updated at operation 2 i-35. If needed, the gNB sets theRQI bit and the RDI bit of the SDAP header to “1” at operation 2 i-40and transmits the data packet to the UE at operation 2 i-45. In theabove operation, the RQI bit and the RDI bit are set through independentprocedures, and the case in which both the RQI bit and the RDI bit areset to “1” is illustrated in the drawing merely to show an example. Atthis time, the UE executes the NAS mapping timer. The condition underwhich the RQI bit of the SDAP header is set to “1” corresponds to thecase in which the RQI bit of the N3 header is set, and the RDI bit isset by determination by the gNB when mapping information between the QoSflow and the RB is updated. The UE receives the data packet from thegNB, and if the RQI of the SDAP header is set to “1”, executes the NASmapping timer at operation 2 i-50. At operation 2 i-55, the UE performsthe reflective QoS operation (AS/NAS mapping rule update) and transmitsan uplink data packet according to the updated information at operation2 i-60. At operation 2 i-65, the gNB transmits the data packet receivedfrom the UE to the CN. If the configured timer expires in the UE and theCN at operation 2 i-70 and operation 2 i-80, the UE and the CN deletethe NAS QoS mapping rule for the corresponding IP packet at operation 2i-75 and operation 2 i-85.

FIG. 2JA illustrates a QoS-related operation, particularly a method ofconfiguring and using a QFI of an SDAP header by a UE in anext-generation mobile communication system according to an embodimentof the disclosure, and FIG. 2JB illustrates a QoS-related operation,particularly a method of configuring and using a QFI of an SDAP headerby a UE in a next-generation mobile communication system according to anembodiment of the disclosure.

The methods with respect to FIGS. 2F, 2G, and 2H of the disclosure maybe largely divided into two scenarios according to methods of usingstatic/dynamic QFI length.

Referring to FIGS. 2JA and 2JB, case 2 j-A corresponds to a UE operationfor the method of dynamically using the QFI length (b bits or 14 bits)and case 2 j-B corresponds to a UE operation for the method ofstatistically using the QFI length (6 bits or 14 bits).

First, in case 2 j-A, the terminal receives SDAP-related configurationinformation from the gNB through an RRC message at operation 2 j-05. Themessage may indicate whether the corresponding DRB uses an SDAP header(RQI, RDI, or QoS flow ID) or may contain an indicator for indicatingwhether an extended QFI is used. The SDAP configuration may be signaledto be applied to each DRB or all DRBs, and an indicator for indicatingwhether the CN supports the extended QFI may be received through a NASmessage along with information on whether the UE supports a NASreflective QoS operation and NAS mapping timer information from the CN.Thereafter, when the UE identifies that the extended QoS flow ID isapplied to the corresponding DRBs, the UE checks an SDAP header of asubsequently received data packet at operation 2 j-10. When both the RQIbit and the RDI bit are set to “0” at operation 2 j-15, the UEdetermines that the previously received QoS mapping rule is continuouslyused, and analyzes the QFI of the received SDAP as a dummy/zero bit of 6bits at operation 2 j-20. For example, it is not required to analyze thecorresponding QFI. Thereafter, when uplink transmission for thecorresponding QoS flow is generated, the UE makes the SDAP headeraccording to the stored QoS mapping rule and transmits the uplink packetat operation 2 j-25. If at least one of the RQI bit or the RDI bit isset to “1” at operation 2 j-15, the UE updates the AS/NAS reflective QoSmapping rule according to the indication of the corresponding RQI andRDI at operation 2 j-30. For example, when the RQI is set to “1”, theNAS mapping rule is updated. When the RDI is set to “1”, the AS mappingrule is updated. Further, when it is configured to apply the extendedQFI to the corresponding DRB at operation 2 j-05, the UE analyzes theQFI field as extended 14 bits at operation 2 j-30 (or QFI 6 bits may beapplied and analyzed when the QFI is equal to or smaller than 63 and QFI14 bits may be applied and analyzed when the QFI is larger than or equalto 64). Thereafter, when uplink transmission for the corresponding QoSflow is generated, the UE makes the SDAP header according to the updatedQoS mapping rule and transmits the uplink packet at operation 2 j-35.

In case 2 j-B, the UE receives SDAP-related configuration informationfrom the gNB through an RRC message at operation 2 j-40. The message mayindicate whether the corresponding DRB uses an SDAP header (RQI, RDI, orQoS flow ID), or may contain an indicator for indicating whether anextended QFI having a fixed value is used. The SDAP configuration may besignaled to be applied to each DRB or all DRBs, and an indicator forindicating whether the CN supports the extended QFI may be receivedthrough a NAS message along with information on whether the UE supportsa NAS reflective QoS operation and NAS mapping timer information fromthe CN. Thereafter, when the UE identifies that the extended QoS flow IDhaving the fixed value is applied to the corresponding DRBs, the UEanalyzes the SDAP for a data packet received later at operation 2 j-45.At operation 2 j-50, the UE updates an AS/NAS reflective QoS mappingrule according to the indication of the corresponding RQI and RDI. Forexample, when the RQI is set to “1”, the NAS mapping rule is updated.When the RDI is set to “1”, the AS mapping rule is updated. Further, inthe above operation, the UE analyzes the QFI of fixed 6 bits andperforms the corresponding operation. Thereafter, when uplinktransmission for the corresponding QoS flow is generated, the UE makesthe SDAP header according to the updated/stored QoS mapping rule andtransmits the uplink packet at operation 2 j-55.

FIG. 2K is a block diagram illustrating an internal structure of a UEaccording to an embodiment of the disclosure.

Referring to FIG. 2K, the UE includes a RF processing unit 2 k-10, abaseband processing unit 2 k-20, a storage unit 2 k-30, and a controller2 k-40.

The RF processing unit 2 k-10 performs a function for transmitting andreceiving a signal through a radio channel, such as band conversion andamplification of a signal. For example, the RF processing unit 2 k-10up-converts a baseband signal provided from the baseband processing unit2 k-20 into an RF band signal, transmits the RF band signal through anantenna, and then down-converts the RF band signal received through theantenna into a baseband signal. For example, the RF processing unit 2k-10 may include a transmission filter, a reception filter, anamplifier, a mixer, an oscillator, a DAC, an ADC, and the like. AlthoughFIG. 2K illustrates only one antenna, the UE may include a plurality ofantennas. Further, the RF processing unit 2 k-10 may include a pluralityof RF chains. Moreover, the RF processing unit 2 k-10 may performbeamforming. For the beamforming, the RF processing unit 2 k-10 maycontrol a phase and a size of each signal transmitted/received through aplurality of antennas or antenna elements. The RF processing unit mayperform MIMO and receive a plurality of layers when performing the MIMOoperation.

The baseband processing unit 2 k-20 performs a function for conversionbetween a baseband signal and a bitstream according to a physical-layerstandard of the system. For example, when transmitting data, thebaseband processing unit 2 k-20 generates complex symbols by encodingand modulating a transmission bitstream. Further, when receiving data,the baseband processing unit 2 k-20 reconstructs a reception bitstreamby demodulating and decoding a baseband signal provided from the RFprocessing unit 2 k-10. For example, in an OFDM scheme, when data istransmitted, the baseband processing unit 2 k-20 generates complexsymbols by encoding and modulating a transmission bitstream, maps thecomplex symbols to subcarriers, and then configures OFDM symbols throughan IFFT operation and a CP insertion. Further, when receiving data, thebaseband processing unit 2 k-20 divides the baseband signal providedfrom the RF processing unit 2 k-10 in units of OFDM symbols,reconstructs the signals mapped to the subcarriers through a FFToperation, and then reconstructs a reception bitstream throughdemodulation and decoding.

The baseband processing unit 2 k-20 and the RF processing unit 2 k-10transmit and receive a signal as described above. Accordingly, thebaseband processing unit 2 k-20 and the RF processing unit 2 k-10 may beembodied as a transmitter, a receiver, a transceiver, or a communicationunit. Further, at least one of the baseband processing unit 2 k-20 andthe RF processing unit 2 k-10 may include a plurality of communicationmodules for supporting a plurality of different radio accesstechnologies. In addition, at least one of the baseband processing unit2 k-20 and the RF processing unit 2 k-10 may include differentcommunication modules for supporting signals in different frequencybands. For example, the different radio access technologies may includea wireless LAN (for example, IEEE 802.11) and a cellular network (forexample, LTE). Further, the different frequency bands may include a SHF(for example, 2 NRHz, NRhz) band and a millimeter (mm) wave (forexample, 60 GHz) band.

The storage unit 2 k-30 stores data, such as a basic program, anapplication, and setting information for the operation of the UE.Particularly, the storage unit 2 k-30 may store information related to asecond access node for performing wireless communication through asecond radio access technology. The storage unit 2 k-30 provides storeddata in response to a request from the controller 2 k-40.

The controller 2 k-40 controls the overall operation of the UE. Forexample, the controller 2 k-40 transmits and receives a signal throughthe baseband processing unit 2 k-20 and the RF processing unit 2 k-10.Further, the controller 2 k-40 records data in the storage unit 2 k-30and reads the data. To this end, the controller 2 k-40 may include atleast one processor. For example, the controller 2 k-40 may include a CPthat performs control for communication and an AP that controls a higherlayer, such as an application layer. The controller 2 k-40 may include amulti-connection processing unit 2 k-42 for processing information whichis a reference for determining whether or not to allow multipleconnections to the UE.

FIG. 2L is a block diagram illustrating a configuration of an NR NBaccording to an embodiment of the disclosure.

Referring to FIG. 2L, the NR NB includes an RF processing unit 2 l-10, abaseband processing unit 2 l-20, a backhaul communication unit 2 l-30, astorage unit 2 l-40, and a controller 2 l-50.

The RF processing unit 2 l-10 performs a function for transmitting andreceiving a signal through a radio channel, such as band conversion andamplification of a signal. For example, the RF processing unit 2 l-10up-converts a baseband signal provided from the baseband processing unit2 l-20 into an RF band signal, transmits the RF band signal through anantenna, and then down-converts the RF band signal received through theantenna into a baseband signal. For example, the RF processing unit 2l-10 may include a transmission filter, a reception filter, anamplifier, a mixer, an oscillator, a DAC, and an ADC. Although FIG. 2Lillustrates only one antenna, the first access node may include aplurality of antennas. In addition, the RF processing unit 2 l-10 mayinclude a plurality of RF chains. The RF processing unit 2 l-10 mayperform beamforming. For the beamforming, the RF processing unit 2 l-10may control the phase and size of each of the signals transmitted andreceived through a plurality of antennas or antenna elements. The RFprocessing unit may perform a downlink MIMO operation by transmittingone or more layers.

The baseband processing unit 2 l-20 performs a function of performingconversion between a baseband signal and a bitstream according to aphysical-layer standard of the first radio access technology. Forexample, when transmitting data, the baseband processing unit 2 l-20generates complex symbols by encoding and modulating a transmissionbitstream. Further, when receiving data, the baseband processing unit 2l-20 reconstructs a reception bitstream by demodulating and decoding abaseband signal provided from the RF processing unit 2 l-10. Forexample, in an OFDM scheme, when transmitting data, the basebandprocessing unit 2 l-20 may generate complex symbols by encoding andmodulating the transmission bitstream, map the complex symbols tosubcarriers, and then configure OFDM symbols through an IFFT operationand CP insertion. In addition, when receiving data, the basebandprocessing unit 2 l-20 divides a baseband signal provided from the RFprocessing unit 2 l-10 in units of OFDM symbols, recovers signals mappedwith subcarriers through an FFT operation, and then recovers a receptionbit string through demodulation and decoding. The baseband processingunit 2 l-20 and the RF processing unit 2 l-10 transmit and receive asignal as described above. Accordingly, the baseband processing unit 2l-20 and the RF processing unit 2 l-10 may be embodied as a transmitter,a receiver, a transceiver, a communication unit, or a wirelesscommunication unit.

The backhaul communication unit 2 l-30 provides an interface forcommunicating with other nodes within the network. For example, thebackhaul communication unit 2 l-30 converts a bitstream transmitted toanother node, for example, the SeNB or a CN from the MeNB, into aphysical signal and converts the physical signal received from the othernode into the bitstream.

The storage unit 2 l-40 stores data, such as a basic program, anapplication, and setting information for the operation of the MeNB.Particularly, the storage unit 2 l-40 may store information on a bearerallocated to the accessed UE and a measurement result reported from theaccessed UE. Further, the storage unit 2 l-40 may store informationwhich is a reference for determining whether or not to allow multipleconnections to the UE. The storage unit 2 l-40 provides stored data inresponse to a request from the controller 2 l-50.

The controller 2 l-50 controls the overall operation of the MeNB. Forexample, the controller 2 l-50 transmits and receives a signal throughthe baseband processing unit 2 l-20 and the RF processing unit 2 l-10 orthrough the backhaul communication unit 2 l-30. Further, the controller2 l-50 records data in the storage unit 2 l-40 and reads the data. Tothis end, the controller 2 l-50 may include at least one processor. Thecontroller 2 l-50 may include a multi-connection processing unit 2 l-52for processing information which is a reference for determining whetheror not to allow multiple connections to the UE.

The embodiments disclosed in the specifications and drawings areprovided merely to readily describe and to help a thorough understandingof the disclosure but are not intended to limit the scope of thedisclosure. Therefore, it should be construed that, in addition to theembodiments disclosed herein, all modifications and changes or modifiedand changed forms derived from the technical idea of the disclosure fallwithin the scope of the disclosure.

While the disclosure has been shown and described with reference tovarious embodiments thereof, it will be understood by those skilled inthe art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the disclosure as definedby the appended claims and their equivalents.

What is claimed is:
 1. A method by a terminal, the method comprising:receiving, from a base station, information for a sounding referencesignal (SRS) configuration; receiving, from the base station, a mediumaccess control (MAC) control element (CE) for activating asemi-persistent (SP) SRS; and transmitting, to the base station, an SRSon a first cell based on the information for the SRS configuration andthe MAC CE for activating the SP SRS, wherein the MAC CE for activatingthe SP SRS includes an indicator for indicating whether serving cellinformation and bandwidth part (BWP) information for a reference signalassociated with spatial relationship are present, wherein the MAC CE foractivating the SP SRS includes the serving cell information and the BWPinformation, in a case that the indicator is set to 1, and wherein theMAC CE for activating the SP SRS does not include the serving cellinformation and the BWP information, in a case that the indicator is setto
 0. 2. The method of claim 1, wherein the serving cell informationindicates an identity of a second cell on which a resource used forspatial relationship derivation for an SRS resource of the SRS islocated, and wherein the BWP information indicates a BWP on which theresource used for spatial relationship derivation for the SRS resourceof the SRS is located.
 3. The method of claim 1, wherein the MAC CEincludes at least one of serving cell information for the SRS, BWPinformation for the SRS, or SRS resource information for an SRS resourceof the SRS.
 4. The method of claim 1, wherein the reference signal isone of a synchronization signal block (SSB), channel state informationreference signal (CSI-RS), or another SRS, and wherein the serving cellinformation and the BWP information are included in the MAC CE, in acase that a cell of the reference signal is different from the firstcell on which the SRS is transmitted.
 5. A terminal comprising: atransceiver; and a controller coupled with the transceiver andconfigured to: receive information for a sounding reference signal (SRS)configuration, receive a medium access control (MAC) control element(CE) for activating a semi-persistent (SP) SRS, and transmit an SRS on afirst cell based on the information for the SRS configuration and theMAC CE for activating the SP SRS, wherein the MAC CE for activating theSP SRS includes an indicator for indicating whether serving cellinformation and bandwidth part (BWP) information for a reference signalassociated with spatial relationship are present, wherein the MAC CE foractivating the SP SRS includes the serving cell information and the BWPinformation, in a case that the indicator is set to 1, and wherein theMAC CE for activating the SP SRS does not include the serving cellinformation and the BWP information, in a case that the indicator is setto
 0. 6. The terminal of claim 5, wherein the serving cell informationindicates an identity of a second cell on which a resource used forspatial relationship derivation for an SRS resource of the SRS islocated, and wherein the BWP information indicates a BWP on which theresource used for spatial relationship derivation for the SRS resourceof the SRS is located.
 7. The terminal of claim 5, wherein the MAC CEincludes at least one of serving cell information for the SRS, BWPinformation for the SRS, or SRS resource information for an SRS resourceof the SRS.
 8. The terminal of claim 5, wherein the reference signal isone of a synchronization signal block (SSB), channel state informationreference signal (CSI-RS), or another SRS, and wherein the serving cellinformation and the BWP information are included in the MAC CE, in acase that a cell of the reference signal is different from the firstcell on which the SRS is transmitted.
 9. A method by a base station, themethod comprising: transmitting, to a terminal, information for asounding reference signal (SRS) configuration; transmitting, to theterminal, a medium access control (MAC) control element (CE) foractivating a semi-persistent (SP) SRS; and receiving, from the terminal,an SRS on a first cell based on the information for the SRSconfiguration and the MAC CE for activating the SP SRS, wherein the MACCE for activating the SP SRS includes an indicator for indicatingwhether serving cell information and bandwidth part (BWP) informationfor a reference signal associated with spatial relationship are present,wherein the MAC CE for activating the SP SRS includes the serving cellinformation and the BWP information, in a case that the indicator is setto 1, and wherein the MAC CE for activating the SP SRS does not includethe serving cell information and the BWP information, in a case that theindicator is set to
 0. 10. The method of claim 9, wherein the servingcell information indicates an identity of a second cell on which aresource used for spatial relationship derivation for an SRS resource ofthe SRS is located, and wherein the BWP information indicates a BWP onwhich the resource used for spatial relationship derivation for the SRSresource of the SRS is located.
 11. The method of claim 9, wherein theMAC CE includes at least one of serving cell information for the SRS,BWP information for the SRS, or SRS resource information for an SRSresource of the SRS.
 12. The method of claim 9, wherein the referencesignal is one of a synchronization signal block (SSB), channel stateinformation-reference signal (CSI-RS), or another SRS, and wherein theserving cell information and the BWP information are included in the MACCE, in a case that a cell of the reference signal is different from thefirst cell on which the SRS is transmitted.
 13. A base stationcomprising: a transceiver; and a controller coupled with the transceiverand configured to: transmit, to a terminal, information for a soundingreference signal (SRS) configuration, transmit, to the terminal, amedium access control (MAC) control element (CE) for activating asemi-persistent (SP) SRS, and receive, from the terminal, an SRS on afirst cell based on the information for the SRS configuration and theMAC CE for activating the SP SRS, wherein the MAC CE for activating theSP SRS includes an indicator for indicating whether serving cellinformation and bandwidth part (BWP) information for a reference signalassociated with spatial relationship are present, wherein the MAC CE foractivating the SP SRS includes the serving cell information and the BWPinformation, in a case that the indicator is set to 1, and wherein theMAC CE for activating the SP SRS does not include the serving cellinformation and the BWP information, in a case that the indicator is setto
 0. 14. The base station of claim 13, wherein the serving cellinformation indicates an identity of a second cell on which a resourceused for spatial relationship derivation for an SRS resource of the SRSis located, and wherein the BWP information indicates a BWP on which theresource used for spatial relationship derivation for the SRS resourceof the SRS is located.
 15. The base station of claim 13, wherein the MACCE includes at least one of serving cell information for the SRS, BWPinformation for the SRS, or SRS resource information for an SRS resourceof the SRS.
 16. The base station of claim 13, wherein the referencesignal is one of a synchronization signal block (SSB), channel stateinformation-reference signal (CSI-RS), or another SRS, and wherein theserving cell information and the BWP information are included in the MACCE, in a case that a cell of the reference signal is different from thefirst cell on which the SRS is transmitted.